Among power conversion apparatuses represented by an inverter, a power semiconductor is used as a major component having rectification and switching functions. Although silicon is currently the mainstream as a material for the power semiconductor, development aimed at adoption of silicon carbide (SiC) excellent in physical properties is proceeding.
Conventionally, techniques for improving reliability of a semiconductor device using SiC includes a technique in which a highly electric field resistant sealing material is inserted between a silicone gel sealing material and a semiconductor to suppress electric field intensity in silicone gel in the vicinity of a termination region of an SiC chip within a range of an electric field resistance (see, for example, PTL 1).